adj. dull·er, dull·est
a. Arousing little interest; lacking liveliness; boring: a dull movie.
b. Not brisk or rapid; sluggish: Business has been dull.
2. Not having a sharp edge or point; blunt: a dull knife.
a. Not intensely or keenly felt: a dull ache.
b. Not bright, vivid, or shiny: a dull brown; a glaze with a dull finish.
c. Cloudy or overcast: a dull sky.
d. Not clear or resonant: a dull thud.
4. Intellectually weak or obtuse; stupid.
5. Lacking responsiveness or alertness; insensitive: half-asleep and dull to the noises in the next room.
6. Dispirited; depressed: a dull mood.
tr. & intr.v. dulled, dull·ing, dulls
To make or become dull.
[Middle English dul; akin to Old English dol.]
dullness, dulness n.
Synonyms: dull, colorless, drab1, humdrum, lackluster, pedestrian, stodgy, uninspired
These adjectives mean lacking in liveliness, charm, or surprise: a dull, uninteresting performance; a colorless and unimaginative person; a drab and boring job; a humdrum conversation; a lackluster life; a pedestrian movie plot; a stodgy dinner party; an uninspired lecture.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.